MONTPELIER — A union hoping to organize home child care providers in Vermont said Friday the leader of the state Senate is going back on his word by not pushing for a vote of the full Senate on a bill that would allow the unionization effort.

“Senator Campbell and I met before the session began. Senator Campbell assured us that our bill would get a fair vote, up or down, on the Senate floor, regardless of the committee vote,” Ben Johnson, president of AFT Vermont, an affiliate of the American Federation of Teachers, said in an email.

In an interview, Campbell called that account “absolutely, absolutely false.” He added, “If my committee was going to hear it and come out with a negative vote, I wouldn’t overrule the committee.”

Campbell’s comments came three days after the Senate Economic Development Committee voted 3-2 to kill a bill that would have allowed home-based child care providers to unionize and negotiate with the state over child care subsidies for low-income working people and regulations that govern the providers.

The legislative process usually begins with bills being studied by a committee which then votes whether to send the measure on to the full House or Senate for a vote. If a committee decides to kill a bill, that in most cases is the end of the story.

As he ran for a second term as Senate leader in December, Campbell garnered support in part by promising supporters of what proponents call “death-with-dignity” legislation that he would push for a floor vote on that bill, even though he personally opposed it and it was likely to get a negative vote in the Judiciary Committee.

Campbell got the chairman of that committee, Sen. Richard Sears, D-Bennington, to agree to send the “death-with-dignity” bill to the floor with a negative recommendation, even though Sears also was an opponent. The Senate ultimately passed an amended bill and sent it on to the House, where it awaits action.

The question facing Campbell now is whether he also promised to follow a similar procedure with other hotly debated measures. AFT officials point to comments Campbell made in January to the Burlington weekly newspaper Seven Days, in which he appeared to say he would support bringing bills to the floor when a majority of his fellow Democrats supported them, even if the committee of origin did not.

In the case of such bills, Campbell told Seven Days, “I believe that they should come to the floor.”

Campbell said he was surprised to see the child care unionization bill voted down in committee, but added that he had not promised and did not intend to bring it to the floor.